Plastically deformable ears of the type which have become known as "Oetiker" ears have been used heretofore with great success and in a variety of different clamp structures, as disclosed, for example, in my prior U.S. Pat. Nos. 2,614,304; 3,082,498; 3,465,793, 3,523,337 and 3,510,918. However, in certain applications, space conditions do not permit any projecting parts such as plastically deformable ears, and therefore require earless clamp structures. My prior U.S. Pat. No. 4,492,004 describes an earless clamp structure which has proved highly successful. In the earless clamp structure as disclosed in this patent, outwardly extending embossments 24 and 25 are provided which are pressed out of the band material and are of at least partially cylindrical shape. Because of space requirements, these embossments must be relatively low in height and therefore require special tools provided with pointed tips for engagement into the openings formed by the embossments. Apart from the costs involved in making such special tools, they additionally entail the disadvantage that their life expectancy is limited due to wear and/or breakage of the tips.
Furthermore, there are limitations on the height, particularly with respect to the inner embossment 25 because this embossment must be able to extend through the slot 27 so that a limited amount of material is available for deformation which in turn limits the height of the embossment of the inner band portion if a certain thickness and therewith strength of the embossment is to be preserved.